M×N wavelength selective switch with compressed port spacing

Abstract

An M×N wavelength selective switch (WSS), may comprise a common port fiber array unit (FAU) configured to emit optical beams with a lateral offset and a beam steering device configured to direct optical beams with an angular offset to add/drop port optical fibers of an add/drop port FAU. The common port FAU may comprise a first set of common port optical fibers arranged in a first column of the common port FAU and a second set of common port optical fibers arranged in a second column of the common port FAU. The second column of the common port FAU may be laterally offset from the first column of the common port FAU. The beam steering device may be configured to selectively direct, in two dimensions, the optical beams with the angular offset to the add/drop port optical fibers.

What is claimed is: 
     
       1. An M×N wavelength selective switch (WSS), comprising:
 a common port fiber array unit (FAU) configured to emit optical beams with a lateral offset, comprising:
 a first set of common port optical fibers arranged in a first column of the common port FAU, and 
 a second set of common port optical fibers arranged in a second column of the common port FAU,
 wherein the second column of the common port FAU is laterally offset from the first column of the common port FAU; 
 
 
 a beam steering device configured to direct the optical beams with an angular offset to add/drop port optical fibers,
 wherein the beam steering device is configured to selectively direct, in two dimensions, the optical beams with the angular offset to the add/drop port optical fibers; and 
 
 an optical element configured to converge the optical beams to a same area of the beam steering device at an angle to cause the angular offset. 
 
     
     
       2. The M×N WSS of  claim 1 , further comprising:
 an add/drop port FAU comprising the add/drop port optical fibers,
 wherein the add/drop FAU comprises a set of add/drop port optical fibers arranged in a column. 
 
 
     
     
       3. The M×N WSS of  claim 1 , further comprising:
 an add/drop port FAU, comprising:
 a first set of add/drop port optical fibers, of the add/drop port optical fibers, arranged in a first column of the add/drop port FAU, and 
 a second set of add/drop port optical fibers, of the add/drop port optical fibers, arranged in a second column of the add/drop port FAU,
 wherein the second column of the add/drop port FAU is laterally offset from the first column of the add/drop port FAU. 
 
 
 
     
     
       4. The M×N WSS of  claim 1 , further comprising:
 a microlens array (MLA) coupled to the common port FAU,
 wherein the MLA comprises, for each of the first set of common port optical fibers and for each of the second set of common port optical fibers, a corresponding microlens, and 
 wherein the MLA is configured to collimate the optical beams when exiting from the first set of common port optical fibers and the second set of common port optical fibers. 
 
 
     
     
       5. The M×N WSS of  claim 1 , further comprising:
 a second optical element configured to convert the lateral offset of the optical beams into a second angular offset of the optical beams. 
 
     
     
       6. The M×N WSS of  claim 1 , further comprising:
 a second optical element positioned between the common port FAU and the beam steering device,
 wherein the second optical element is configured to convert the lateral offset of the optical beams into a second angular offset of the optical beams. 
 
 
     
     
       7. The M×N WSS of  claim 1 , wherein
 the optical element is positioned between the beam steering device and an additional beam steering device. 
 
     
     
       8. An M×N wavelength selective switch (WSS), comprising:
 a common port fiber array unit (FAU), comprising:
 a first set of common port optical fibers and a second set of common port optical fibers arranged in a one-dimensional linear array of the common FAU,
 wherein the first set of common port optical fibers and the second set of common port optical fibers are positioned alternatingly in the one-dimensional linear array of the common FAU; 
 
 
 a microlens array (MLA) coupled to the common port FAU, comprising:
 a first set of microlenses and a second set of microlenses arranged in a one-dimensional linear array of the MLA,
 wherein the first set of microlenses and the second set of microlenses are arranged in an alternating lateral offset pattern in the one-dimensional linear array of the MLA, and 
 wherein, the first set of microlenses are coupled to the first set of common port optical fibers and the second set of microlenses are coupled to the second set of common port optical fibers; 
 
 
 a beam steering device configured to selectively direct optical beams at an angular offset to add/drop port optical fibers of an add/drop port FAU; and 
 an optical element configured to converge the optical beams to a same area of the beam steering device at an angle to cause the angular offset. 
 
     
     
       9. The M×N WSS of  claim 8 , further comprising:
 the add/drop port FAU,
 wherein the add/drop FAU comprises a set of add/drop port optical fibers arranged in a one-dimensional array of the add/drop port FAU. 
 
 
     
     
       10. The M×N WSS of  claim 8 , further comprising:
 the add/drop port FAU, comprising:
 a first set of add/drop port optical fibers arranged in a first one-dimensional array of the add/drop port FAU, and 
 a second set of add/drop port optical fibers arranged in a second one-dimensional array of the add/drop port FAU,
 wherein the second one-dimensional array of the add/drop port FAU is laterally offset from the first one-dimensional array of the add/drop port FAU. 
 
 
 
     
     
       11. The M×N WSS of  claim 8 , wherein the add/drop port FAU comprises a two-dimensional array of add/drop port optical fibers,
 wherein the beam steering device is configured to tilt around an axis associated with a first dimension of the two-dimensional array and an axis associated with a second dimension of the two-dimensional array. 
 
     
     
       12. The M×N WSS of  claim 8 , wherein the common port FAU and the MLA are configured to emit a first set of optical beams, of the optical beams, interleaved with a second set of optical beams, of the optical beams,
 wherein the first set of optical beams and the second set of optical beams have a second angular offset. 
 
     
     
       13. The M×N WSS of  claim 12 , wherein the beam steering device comprises at least one of:
 a tilting micro-electro-mechanical system (MEMS) mirror array; 
 a liquid crystal on substrate (LCOS) phased array; 
 a tiltable mirror; 
 a controllable diffractive element; or 
 a controllable refractive element. 
 
     
     
       14. The M×N WSS of  claim 12 , further comprising:
 a second optical element configured to converge the first set of optical beams and the second set of optical beams to a particular area of the beam steering device. 
 
     
     
       15. An M×N wavelength selective switch (WSS), comprising:
 a laterally offset microcollimator array (MCA), comprising:
 a one-dimensional fiber array unit (FAU) coupled to a laterally offset one-dimensional microlens array (MLA), or 
 a laterally offset two-dimensional FAU coupled to a laterally offset two-dimensional MLA; 
 
 a beam steering device, comprising:
 one or more elements for selectively directing optical beams at an angular offset; and 
 
 an optical element configured to converge the optical beams to a same area of the beam steering device at an angle to cause the angular offset. 
 
     
     
       16. The M×N WSS of  claim 15 , wherein:
 the one-dimensional FAU comprises:
 a first set of port optical fibers and a second set of port optical fibers arranged in a one-dimensional linear array of the one-dimensional FAU,
 wherein the first set of port optical fibers and the second set of port optical fibers are positioned alternatingly in the one-dimensional linear array of the one-dimensional FAU; and 
 
 
 the laterally offset one-dimensional MLA comprises:
 a first set of microlenses and a second set of microlenses arranged in a one-dimensional linear array of the laterally offset one-dimensional MLA,
 wherein the first set of microlenses and the second set of microlenses are arranged in an alternating lateral offset pattern in the one-dimensional linear array of the laterally offset one-dimensional MLA, and 
 wherein, the first set of microlenses are coupled to the first set of port optical fibers and the second set of microlenses are coupled to the second set of port optical fibers. 
 
 
 
     
     
       17. The M×N WSS of  claim 15 , wherein:
 the laterally offset two-dimensional FAU comprises:
 a first set of port optical fibers arranged in a first column of the laterally offset two-dimensional FAU, and 
 a second set of port optical fibers arranged in a second column of the laterally offset two-dimensional FAU,
 wherein the second column of the laterally offset two-dimensional FAU is laterally offset from the first column of the laterally offset two-dimensional FAU; and 
 
 
 the laterally offset two-dimensional MLA comprises:
 a first set of microlenses arranged in a first column of the laterally offset two-dimensional MLA, and 
 a second set of microlenses arranged in a second column of the laterally offset two-dimensional MLA,
 wherein the second column of the laterally offset two-dimensional MLA is laterally offset from the first column of the laterally offset two-dimensional MLA. 
 
 
 
     
     
       18. The M×N WSS of  claim 15 , wherein the one-dimensional FAU and the laterally offset one-dimensional MLA are configured to emit or receive the optical beams with a lateral offset. 
     
     
       19. The M×N WSS of  claim 15 , wherein the laterally offset two-dimensional FAU and the laterally offset two-dimensional MLA are configured to emit or receive a first set of optical beams, of the optical beams, interleaved with a second set of optical beams, of the optical beams. 
     
     
       20. The M×N WSS of  claim 15 , further comprising:
 an additional MCA configured to emit or receive the optical beams,
 wherein the additional MCA comprises one of the following:
 a one-dimensional first additional FAU coupled to a non-laterally offset one-dimensional additional MLA, 
 a one-dimensional second additional FAU coupled to a laterally offset one-dimensional additional MLA, or 
 a laterally offset two-dimensional additional FAU coupled to a laterally offset two-dimensional additional MLA.